Creatine monohydrate is the most well-researched performance supplement in existence. Its efficacy for increasing maximal strength, power output, and lean mass is well-established across hundreds of studies. The loading question — whether to take 20 g/day for a week or simply start at 3–5 g/day — is largely settled, but the answer is not widely understood.
What Creatine Actually Does
Creatine is stored in skeletal muscle primarily as phosphocreatine (PCr). During high-intensity, short-duration exercise (sprinting, heavy lifting, explosive movements), the body uses PCr to rapidly regenerate ATP — the direct energy currency of muscle contraction.
Supplementing creatine increases intramuscular PCr stores by approximately 20–40% above baseline, which:
- Extends the duration of maximal power output before fatigue sets in
- Accelerates PCr resynthesis between sets
- Supports greater training volume at high intensities
- Promotes water retention within muscle cells, which may directly stimulate protein synthesis
The performance benefit comes specifically from the increase in muscle creatine concentration, not from the act of supplementation itself. This is why the loading question is really a question about how quickly you want to reach full saturation.
How Loading Works
The classic loading protocol from Hultman et al. (1996) involves:
- 20 g/day split into 4 × 5 g doses for 5–7 days
- This saturates muscle creatine stores to approximately 150–160 mmol/kg dry mass within 5–7 days
- After saturation, 2–3 g/day maintains elevated stores
During loading, intramuscular creatine reaches saturation rapidly, meaning training benefits are experienced within the first week of supplementation.
How Maintenance Dosing Works Without Loading
The alternative is to start directly at a maintenance dose:
- 3–5 g/day continuously without a loading phase
- Muscle creatine concentration reaches the same saturated level as loading, but takes 3–4 weeks rather than 5–7 days
The end state is identical. Both approaches produce the same peak muscle creatine concentration — loading simply gets there faster.
For most people, this distinction is irrelevant. The marginal benefit of saturation in week 1 versus week 4 is negligible over a multi-month training block.
The GI Side Effects of Loading
The practical downside of loading is gastrointestinal discomfort. At 20 g/day, a significant proportion of people experience:
- Bloating and cramping: large creatine doses draw water into the gut before absorption, causing osmotic effects
- Diarrhoea: reported in 5–7% of people on the loading protocol
- Nausea: particularly when doses are taken on an empty stomach
Splitting 20 g into 4 × 5 g doses reduces but does not eliminate these effects. Taking creatine with meals and adequate water (400–500 ml per dose) also helps. However, the simplest solution is to skip loading entirely, since the end result is the same.
What Happens If You Forget a Day
Once muscles are saturated, missing a single day has minimal impact. Intramuscular creatine stores deplete over 4–6 weeks without supplementation — a single missed dose is insignificant. This is different from supplements with short half-lives (e.g., caffeine) where daily timing matters.
The Verdict: Skip the Loading Phase
For the vast majority of people — especially those not preparing for a competition in the next 2 weeks — there is no practical benefit to loading:
- Same outcome: identical peak muscle creatine concentration
- Lower GI risk: 3–5 g/day produces minimal to no GI distress
- Simpler protocol: one scoop per day, any time, with any beverage
- Cost-effective: 20 g/day for 7 days uses 140 g of creatine; 5 g/day for the same period uses 35 g
The recommendation: start at 5 g/day of creatine monohydrate. Take it consistently. Do not worry about timing — pre or post-workout, morning, evening, all produce equivalent muscle saturation over time. Wait 3–4 weeks before expecting the full performance benefit.
Creatine Form: Monohydrate Wins
Creatine monohydrate is the only form with robust long-term evidence. Marketing variants — creatine HCl, buffered creatine (Kre-Alkalyn), creatine ethyl ester — are not supported by evidence of superior efficacy and are considerably more expensive.
The only claimed advantage of alternative forms is reduced GI side effects. Since a standard 5 g/day maintenance dose of monohydrate produces minimal GI effects for most people, this advantage rarely materialises in practice.
Practical Supplement Stack Position
Creatine is one of the few supplements with consistent, meaningful performance benefits supported by meta-analyses (Lanhers et al., 2017; Rawson & Volek, 2003). In a priority-ordered supplementation list, it sits alongside protein and caffeine as a tier-1 supplement for resistance-trained athletes.
For a full picture of creatine’s benefits, dosing considerations, and optimal timing strategies, see creatine benefits, dosage, and timing.
Summary
- Loading (20 g/day for 5–7 days) saturates muscle creatine in 5–7 days
- Maintenance dosing (3–5 g/day) reaches the same saturation in 3–4 weeks
- The final muscle creatine concentration is identical — only the speed differs
- Loading frequently causes GI distress; maintenance dosing rarely does
- For most people: skip loading, start at 5 g/day, and be consistent
GYMRPG’s workout log records supplement entries alongside session data, storing start dates and progression metrics in the same log.
Sources
- Hultman E et al. (1996) — Muscle Creatine Loading in Men. Journal of Applied Physiology, 81(1), 232–237.
- Lanhers C et al. (2017) — Creatine Supplementation and Upper Limb Strength Performance: A Systematic Review and Meta-Analysis. Sports Medicine, 47(1), 163–173.
- Rawson ES & Volek JS (2003) — Effects of Creatine Supplementation and Resistance Training on Muscle Strength and Weightlifting Performance. Journal of Strength and Conditioning Research, 17(4), 822–831.
- Greenhaff PL et al. (1994) — Influence of Oral Creatine Supplementation of Muscle Torque During Repeated Bouts of Maximal Voluntary Exercise in Man. Clinical Science, 87(4), 415–419.